Electric condenser



June 15 1926.

C. s. GERBER ELECTRIC coNDENsEa -Filed April 1, 1925 FIE. I-

FIE-]I.

MW d/w 4.10

lil 3 Patented .lune l5,

UNITED sra'rns CARL S. GERBER, OF PITTSBURGH, PENNSYLVANIA.

. v ELECTRIC CGNDENSER.

Application led April l,

lVIy invention relates to electric condensers, and consists in a variable condenser of simple structure, great durability, and capable of a Wide range of service. It is applieable generally, but I have developed it as a condenser for service in adomestic receiving set ot a `Wireless telephony system, and in such development I shall, by Way of example, show and describe it. c In the drawings Fig. I is a view in vertical and medial section of a condenser embodying my invention; Figs. II, III, and IV, are views in transverse section, on the planes respectively indicated in Fig. I by the lines II-II, IIL-III, and IV-IV. Fig. V is a view in side elevation. Y

Block I isa block of dielectric, ot' bal-:elite or of other suitable material, in this instance of substantially cylindrical form, bearing in its head, and as here shown in both heads, plates 2 of conducting material, of aluminum, for example. These plates are overlain by thin sheets 3 of suitable dielectric, ordinarily mica. The plates 2 are of strip form, and in this instance are incompletely annular, concentrically laid upon the cylindrical block l; they taper from end to end, and as sume therefore the general spiral torni clearly shown in Fig. III. Through the block l laterally, and from the narrow ends of the plates 2, entend electric leads which terminate in binding-posts ll.

'Ivvo plates 5 are provided, to cooperate with plates 2 in a'ording the condenser effeet, and as will be seen in Fig. II these plates 5 are approximately the shape and size of plates 2.

Means are provided for sustaining the plates 5 remote 'from the mica covered lates 2 and for bringing them progressively of their longitudinal extent into bearing upon the outer surfaces ot the mica plates 3. Accordingly the block l, carrying plates 2 with their mica coverings 8, is mounted in a frame which consists oit end plates 6 and tension bolts 7. The block l is rigidly borne, centrally Within this trame.

A shaft S, axially borne the trarne, extends aXially through block l.r It is rotatable in its mounting, and, that it may be manually rotated, it is provided with the milled head 9. The shaft 8 carries cylindrical blocks l() of balrelite or of equivalent dielectric material, and these blocks are pro vided peripherally with spirally entend slots 1l. .at one end these slotje 1925. Serial N0. 19,762.

through the cylindrical heads orp the blocks, and form radially extending slots in the cylinder heads. These slotted heads ot these cylindrical blocks are the heads which in the assembly are adjacent block l. The blocks IO are mounted at proper intervals from block l to receive into the space' between them and block l the plates 5, and to press plates 5 'firmly upon the mica sheets 3 which overlie the plates 2.

rlhe plates 5 are anchored at their narrow ends in bloelr l, and from such anchorage they entend into the slots ll of the blocks lO, which open to receive them, as I have said, through the heads of rthe cylindrical. blocks l0.

As the blocks l() borne by shaft S are turned Within the frame and relatively t-o ynection is made, and, circuits being established between these anchor-ages severally and the binding posts 4, and sources of electric energy being included in those circuits, the plates 2 and 5, to the extent that they entend in close engagement upon opposite sides of the mica plates 8, become condenser plates. eind proportionately as the blocks 10 are turned, and the plates 5 brought to greater or less extent to such close engagement upon the mica plates, the etcacy orn the condenser is increased or diminished.

Consideration of F ig. II will show that in the use of the instrument the companion condenser plates may be brought to opposition with the sheet ot dielectric between over an area which increases from a single point of overlap, at a, to any desired degree, Within the range of the particular instrument; and that by virtue of the tapered shape and the relative arrangement of the two strips tie rate of increase ot this area of opposition increases as the actual areaot opposition increases. Thus ner adjustmentbecomes possible When actual values are less, t will be perceived there is essential the bleek i 5 extend in the direction of such relative movement. .It is then a matter of convenu ience that the blocks are cylindrical vand the relative movement rotary.'

I claim as my invention:

Al. A variable electrical condenser. including two blocks of insulating material arranged ace to face and movable one relatively to the other, two strips of conducting material and asheet of insulating material, the two strips of conducting material being anchored each at one end tooneof said blocks, with the sheet of insulating material between them, and extending from such Y,anchoragev in the direction of relative movement between said blocks, the second blockv being slotted transversely of the direction of such'relative movement, theouter oftv said strips extending when the parts are assembled from its anchorage, through the slots in the second block, -and'means for making electrical connections with'said strips severally at their anchored ends.

2. A variable electrical condenser including two blocks of insulating material arranged face to ifafce and movable one relatively to the other, two strips of conducting material of which one is flexible and a sheet of insulating material, the two strips of conducting material being anchored each at one end to one of said blocks, with the sheet of insulating materiallbetween them and the flexible strip outermost, the strips extending from suchv anchorage in the direction of relative movement between said blocks, the second block being provided with a slot inclined to the meeting plane between the blocks, opening through the surface of engagement' with the companion block and in extent equalling the flexible strip in length,

the flexible vstrip when the arefassem-VV n "if l bled extendingv from its anchorage into ,the ff g slot in the slotted block, and means for mak.-

terial faced with sheets of dielectric, two

sheet oit dielectric between, and Y a vslotted tively to the Vstrips i-r'st named and'Y receiving within their slots when the Vparts arel assembled '.'tlie otherwise free ends of' the flexible strips, and a bindingV postffor each of said relatively stationary strips,V

4. In ka variable condenser a 'bloclijof insulation vbearing a strip olf conducting mal terial faced with a sheet 'of dielectric, 'a secl 4ond and flexible strip of conducting 'mate-f rial anchored at one end tosaid block ott in--` sulation and adapted progejssivelyjto over-f J lie the strip iirst' named withthe sheetofg:VV 'I dielectric-between, and a second block of insulation movable'in `face toV tace relation t'othe first, and provided with a'slotyopen-J ing 'through the companion-facing'surface and extending through a length/as great as the length of said flexible strip, :the vsaid` 'flexible 'str-ip, when the parts are'asseinbledr extendingV at `its" otherwise free Yend withinVK the slot in the relatively movable 'blocln'and means for, making Velectrical contact Vwith f said strips severally atl their anchored ends.

' In testimony whereof I have hereunto kset k my hand. Y l Y CARL S.v

5o Yflexible strips of conducting material secured y l each at one end and there connected to'sepl .Y arate binding'posts and adapted progressivef j' 'ly to overlie the strips firstnamedfwith the if V365' carrier of insulating material movablel-'ela- 3 Y 

